Screening Of Lactobacillus For Efficient Cholesterol-Lowering And Study On Its Mechanisms

Overmuch cholesterol in the blood and dietary has been recognized as a major risk factor for coronary heart diseases and colon cancer. Because of the associated risk of heart disease, there has been an upsurge in finding ways to lower plasma cholesterol levels in human. Several studies have indicated that consumption of certain Lactobacillus strains and its cultured dairy products resulted in reduction of serum cholesterol concentrations. However, the rules for screening of cholesterol-lowering strains and its mechanisms were not very clear. This paper could be divided into three parts: strains isolation from health youths and children's feces and identification by molecular biological methods; evaluation of cholesterol-lowering Lactobacillus strains with their bile tolerance, cholesterol removal in vitro and deconjugation of sodium taurocholate; study on the mechanisms of cholesterol removal.17 Lactobacillus strains were isolated and identified into species by sequence of 16S rDNA PCR products. They were used for the screening of potential cholesterol-lowering strains.Among the 14 strains from 6 species, 11 strains were resistant to bile salts mixture resembled human bile (lag time, LT<2.00h). 4 strains were resistant to 6mM sodium taurocholate. As a whole, sodium taurocholate was more toxic than sodium glycocholate.The results of in vitro cholesterol removal of 14 strains showed that,...